Power hammer with reaction force absorbing means

ABSTRACT

A pneumatic hammer is disposed in a pneumatic recoil device and positioned by a pair of hydraulic cylinders so that by operating a control lever an operator can position the pneumatic hammer and by depressing a foot pedal he can control the striking force delivered by the pneumatic hammer.

United States Patent Vogeleer [4 Aug. 7, 1973 POWER HAMMER WITH REACTION 913,970 3/1909 Parfitt 173/1 12 FORCE ING ME N 1,688,020 10/1928 Santos 173/159 3,456,744 7/1969 Aitschuler 173/139 X [75] Inventor: John P. Vogeleer, Greensburg, Pa. 4

[73] Assignee: Westinghouse Electric Corporation, Primary Examiner Emest R Purser P'ttsburgh' Attorny-AQT. Stratton, Fred .1. Baehr, Jr. et a1. [22] Filed: Sept. 29, 1971 i [21} Appl. No.: 184,677

[57] ABSTRACT [52] [1.8. Ci. 173/43, 173/139 A pneumatic hammer is disposed in a pneumatic recoil [51] It ll. Cl. E216 11/02 device and positioned by a pair of hydraulic cylinders [58] Field of Search 173/43, 1 12, 139, so that by operating a control level. an operamr can 173/159 sition the pneumatic hammer and by depressing a foot pedal he can control the striking force delivered by the [56] References Cited pneumatic hammen UNITED STATES PATENTS Modrak et a1. 173/43 X 12 Claims, 7 Drawing Figures PAIENTED 7M5 3.750.764

sum 1 0r 4 FIG. I

PATENIEM 71975 SHEET 3 OF 4 FIG?) PATENTED 7975 3. 750.764

saw u or 4 Fl 7 I39 jISG I57 POWER: HAMMER WITH REACTION FORCE ABSORBING MEANS BACKGROUND-OF THE INVENTION 2 lock the carriage 3 in position, when the hammer I is operating. w

An operating platformll is disposed above the base 5 and ascissors lift 13' is disposed between the platform 11 and the base 5. The scissors lift 13 is hydraulically operated to raise the operatingplatform 11 so that the hammer 1 can be positioned adjacent the workpiece (not shown). a j

A turret 15, containing the hammer l, is rotatably at' tached to the operating platform 11 and comprises a disc-shaped base 17 rotatably mounted on a flange 19,

the operator, making the use of the pneumatic hammer tiring and in some instances jolt the operator to such an' extent that hiseyesightbecomes blurred, making it im- 'possible'for him to assess the results of his work. Therefore, a device which absorbsthereactionforces and allows the operator toposition the hammer with a minimum effort, will relieve fatigue, increase productivity, and improve the quality of the'work performed using such air hammers.

SUMMARYOF THEINVENTION In general, a power driven hammer made inaccordance with this invention comprises a device for repeatedly impacting a workpiece,a device for absorbing the reaction forces resultingfro'mtheoperation of the impacting device, a device for holding a portionof the force absorbingdeviceJge'neraIIy within a plane, a device for moving the portion of *the force absorbingdevice in any direction within'aportionoftheplaneand a device for controllingthe movement of the portion of the force absorbing device within the portion of the plane.

BRIEF DESCRIPTION OF THE DRAWINGS I The objects and advantages of thisinvention will be come more apparent from reading the following detailed description in connectionwith the accompanying drawings, in which:

FIG. 1 is an elevational view of a portable power driven hammer made in accordance with this invention;

FIG. 2 is an enlarged partial sectional view taken on line Il--ll of FIG. l;

. FIG. 3 isa sectional view taken onlineIII-Illof FIG.

FIG. 4 is an enlarged partial line lV-IV 0F FIG. 2;. j

FIG. 5 is a hydraulic flow diagram pertinent to this invention; v

sectional view taken on FIG. 6 is a pneumatic flow-diagram pertinent to this inventiomand r FIG. 7 is a wiring diagram'pertinent to this invention.

BRIEF DESCRIPTIONOF THE PREFERRED EMBODIMENT which is fastened to a collar 21 extending upwardly from the operating platform 11. Clamping members 23 are adapted to pull the disc-shaped base 17 tightly against the flange 19 so that when the hammer is operating the turret 15 is prevented from rotating. A rectangular shaped plate 25 is fastened to the upper surface of the disc-shaped base 17 and has support plates 27 and 29 extending upwardly from parallel sides thereof. Gusset plates 31 and 33 are welded to the support plates 27 and 29, respectively, and to the disc-shaped base plates 17. A pair of horizontal support bars 35 and 37 are disposed between the support plates 27 and 29,;

adding rigidity to the turret 15. The support bars 35 and 37 are fastened to spacer blocks 39, which are secured to the support plates 27 and 29.

A Y-shaped plate 41 is slidablydisposed between the support'bars 35 and 37. A servo-motor or hydraulic cylinder 43 fastens to the lower end of the plate 41 and ispivotally connected 'tothe rectangular shaped plate 25 by a clevis type mounting bracket 45. The hydraulic cylinder 43acts as a drive to movethe Y-shaped plate 41 upwardly and downwardly as it is stroked.

A second servo-motor or hydraulic cylinder 47 is pivotally connected to one of the branches of the Y- shaped plate 41 by aclevis type mounting bracket 49 and to a support arm 51 extending upwardly and, outwardly from the vertical support plate 29by another clevis type mounting bracket- 53. The hydraulic cylinder. 47 is disposed to move the Y-shaped plate sideways, or tothe right or to the left, as shown in FIGS. 7

l and 2. i

The hammer l is disposed in a recoil device 55,

which will be described in detail hereinafter, and the recoil device 55 is clamped in a collar 57, which has a locking lever 59, which is rotated to lockor loosen the Referringnow to the drawings in detail, FIG. 1 shows a power driven or pneumatic hammer I, mounted on a carriage 3. The carriage 3 has a base plateS, which the collar so that the recoil device can slide back and forth with respect to the collar 57. The collar 57 has diametrically opposed tr'unnion's 61 which extend out radially and are pivotally disposed in clampingblocks 63 fastened to the branches of the Y-sh'aped plate 4!. Each clamping block 63 has a locking lever 64, which is turned in one direction to clamp the trunnions6-l to the block 63 and in the other direction to release the trunnions so that the hammer I can be adjusted to form various angles with respect to the Y-shaped plate 41.

An L-shaped plate 65 fastens to one of the branches of the Y-shapedplate 41 and extendsoutwardly therefrom, so that the foot portion thereof extends downwardly. A joy stick or control rod 67 is pivotally mountedat the heel of the L-shaped plate 65 in a spherical bearing 69 allowing the control rod 67 to move in any angular direction. Four screw plungers 70 are equally spaced radially around the control rod forming a bias means to return the control rod to a neutral position when the rod is released.

A control valve 71 for controlling the flow of hydraulic fluid to and from the hydraulic cylinder 43, which moves the Y-shaped plate 41 upwardly and downwardly is disposed on the foot of the L-shaped plate 65 and a control valve 73 for controlling the flow of hydraulic fluid to and from the hydraulic cylinder 47 which moves the Y-shaped plate 41 to the right or left, is mounted on the leg portion of the L-shaped plate 65. Links 75 and 77 have spherical pivotal connections 79 at the ends thereof and connect the control valves 71 and 73, respectively, to the control rod 67, allowing the control rod 67 to move in any angular direction and the stems of the control valves 71 and 73 to move rectilinearly.

FIG. 4 shows the recoil device 55, which absorbs the reaction forces produced by the operation of the hammer 1, and which comprises a pair of concentric cylinders 81 and 83 one disposed within the other. Each of the cylinders 81 and 83 has an annular step 85 and 87, respectively, which cooperates to form an end of an an FIG. 6 shows a pneumatic diagram, wherein pressurized air from a supply (not shown) flows through a pneumatic hose 113, which connects to and wraps around a reel 115, which is mounted on the operating platform 11. A pneumatic conduit or hose 117 extends from the reel 115 and is in communication with the hammer l and the recoil device 55. A filter 119, pressure regulator 121, automatic lubricator 123 and foot control valve 125 are disposed in series in the conduit 117 to control and condition the air supplied to the hammer 1 and recoil device 55.

FIG. 7 shows a wiring diagram, in which three phase power is supplied through lines L1, L2, and L3, which form a cable which wraps around a cable reel 127 and extends therefrom. A transformer 129 has its primary winding electrically connected to lines L1 and L2 and its secondary winding electrically connected to conductors 131 and 132. A fuse 133 is disposed in conductor 131 adjacent the corinection to the secondary windnular chamber 88 disposed between the cylinders. The

outer cylinder 81 has an inlet port 89 disposed adjacent the step 85 for admitting pressurized air to the annular chamber 88 otherwise the cylinders 81 and 83 are imperforate. The steps 85 and 87 are generally the same size, the step 85 in the outer cylinder being formed by counter-boring and the step 87 in the inner cylinder 83 being formed by turning down a portion of the outer surface of the inner cylinder 83. Seals 91 and 93 are disposed in the cylinders 81 and 83, respectively, adjacent opposite ends thereof to minimize air leakage from the annular chamber 88. A split sleeve 95 is disposed within the inner cylinder 83 and is adapted to cooperate with a machined surface on the hammer 1 to securely hold the hammer within the sleeve 95. A retainer ring 97 is fastened to one end of the inner cylinder 83 and extends inwardly providing a lip to retain the sleeve 95 within-the inner cylinder 83. A retaining flange 99 is fastened to the other end of the inner cylinder 83 and extends radially inwardly and outwardly therefrom to keep the inner cylinder 83 within the outer cylinder 81 and to keep the sleeve 95 contained within the inner cylinder 83. FIG. 5 shows a hydraulic diagram in which fluid fro a reservoir 101 is pressurized by a pump 103 and the pressurized fluid flows through a supply conduit 105 to control valves 71 and 73. The control valves 71 and 73 are adapted to be actuated by the control lever 67 to cause pressurized fluid to flow to one side of the piston disposed in the double acting hydraulic cylinders 43 and 47, respectively, and simultaneously drain hydraulic fluid from the other side of the pistons of the double acting cylinders to cause the piston rods of the cylinders 43 and 47 to move generally in the same direction as the control rod 67 is moved. Fluid drained from the other side of the pistons of the double acting cylinders 43 and 47 flows through the control valves 71 and 73 and a drain conduit 107 to the reservoir 10!. A pressure gauge 109 is in communication with the supply conduit 105'to indicate the pressure therein, and a pressure relief or control valve 11 1 is disposed in communication with the supply conduit 105 and with the drain conduit 107. The pressure relief valve 111 is adapted to bypass pressurized fluid from the supply to the drain conduit when the pressure in the supply conduit reaches a predetermined value.

ing of the transformer. A grounded receptacle is connected across the conductors 131 and 132 as shown in FIG. 7. Disposed in parallel with the receptacle 135 is a control circuit 137 for a motor 139 which drives the hydraulic pump 103. The control circuit 137 comprises two parallel combinations connected in series across conductors 131 and 132. The first parallel combination is electrically connected to the conductor 131 and contains a momentary pushbutton normally open switch PBl connected in parallel with a normally open contact A1 of a contactor having a coil A. The second parallel combination is connected to the first parallel combination at junction 141 andto the conductor 132 and comprises a momentary normally closed pushbutton switch PB2 connected in series with normally closed contacts B1 and C1 and the contactor coil A. Connected in parallel with the hereinbefore mentioned series is an indicating light bulb 143.

The motor 139 is shown connected to lines L1, L2, and L3 by conductors 145, 146, and 147, respectively. Conductors 145 and 147 have heaters B and C, which control the thermally operated contacts B1 and C1 disposed in series with the normally open contacts A2 and A4, respectively. Conductor 146 has a normally open contact A3 disposed therein. A transformer 149 has its primary windings electrically connected to lines L2 and L3 and its secondary windings electrically connected to the conductors 151 and 152 which are connected to a controlcircuit 153 containing two parallel combinations, which operate the scissors lift 13. The first portion of the parallel combination contains two normally open pushbutton switches P83 and P84 connected to conductor 151 in parallel and connected to the conductor 154 through the series combination of two normally closed contacts D1 and E1 and a contactor coil F. The second portion of the parallel combination comprises two momentary normally open pushbutton switches PBS and P136 connected in parallel and connecting line 151 to 152 through a solenoid 155, which operates a valve 156 to drain hydraulic fluid from a hydraulic cylinder (not shown), which operates the scissors lift 13. v

' A motor 157 which drives a hydraulic pump, which delivers pressurized hydraulic fluid to the hydraulic cylinder to operate the scissors lift 13 is electrically connected to line L1, L2 and L3 by the conductors 159, 160 and 161, respectively. Conductors 159 and 161 have heaters D and E for thermally activated switches disposed in series with normally open contacts Fl and F3, respectively, and conductor 160 has a normally open contact F3 disposed therein. t p

The operation of the hammer is as follows. The earriage 3 isrolled to the desired location and the pads 9 are depressedto engage the floor and lock the carriage .3 in place. The electrical cable containing linesLl,'L2

and L3 is unrolled from the cable reel 127 and connected to a suitable power supply source. The hose 1 13 is unrolled from the reel 115 and connected to a suitable supply of pressurized air. The pushbutton switch FBI is depressed energizing the contactorcoil A which closes contacts A1, which lock in the coil A and closes contacts A2, A3 and A4 causing the motor 139 to run driving the hydraulic pump 103 which supplies hydrautoo high, either pushbutton PBS, which is disposed on the operatingplatform l l, or P86, which is disposed on the carriage 3, may be depressed to energize the solenoid 155 to open the valve 156 which allows hydraulic fluid to drain from the hydraulic cylinder which controls the scissors jack and lowersthe operating platform 11. The valve 156 is only open while the pushbutton PBS or P86 is depressed, thus controlling the descent of the platform. With the operating platform 11 at the rproper elevation the turret 15 maybe rotated by loosening the clamping members 23. Thelocking levers 59 and 64 are also loosened to pivot the hammer about the trunnions 61 and move the hammer back and forth within the collar 57 to correctly position the hammer with respect to the workpiece. The clamping members 23 and locking levers 59 and64 are then tightened to securely fasten the hammer in place with respect to the workpiece.By depressing the pedal, on the foot control valve 125, the operator initiates the operation of the hammer l and controls the impact force it delivers. The recoil device 55 also responds to the operation of the footoperated controlvalve 125 to vary the pressure in the annular chamber 88 to provide a resistance force, which varies directly with the impact force delivered by the hammer. The'hammer l is moved about the workpiece by moving the control rod 67 in the direction, in which it is desired to move the hammer, and as noted hereinbefore when the control rod is released, it will return to a neutral position and the hammer will remain in its present position.

Thus, the operator can accurately control the positioning of the hammer and the impact force exerted by the hammer with a minimal effort, increasing this productivity by relieving fatigue, and increasing the quality of his work by providing more accurate control of the positioning of the hammer than could be provided manually.

What is claimed is:

l. A power driven hammer comprising:

means for repeatedly impacting a workpiece,

means for absorbing the reaction forces resulting from operating the impacting means,

means for holding a portion of said force absorbing means generally within a single plane, means for moving said portion of said force absorbing means in any direction within a portionof said plane, and g,

means for controlling the movement"ofisaid portion of said force absorbing means within said portion of said plane, the said force absorbing means comprises a pair of concentric cylinders, one cylinder being slidably disposed within the other and each cylinder having an annular step, said steps registering to form an annular chamber, one of said cylinders being imperforate except for a single port for supplying pressurized fluid to said chamber, the other cylinder being imperforate.

2. A power driven hammer as set forth in claim 1, wherein said force absorbing means further comprises sealing means disposed on opposite sides of said chamber to minimize leakage therefrom.

3. A power driven hammer as set forth in claim 1, wherein the means for moving the force absorbing means comprises a pair of drives each adapted to generally move rectilinearly, the drives being coopera tively associated with each other and with the force absorbing means so that the portion of the force absorbing means may be moved in any direction in the portion of a single plane.

4. A power driven hammer as set forth in claim 3, wherein the control means comprises a rod and a modulating means for operating each drive, said rod, modulating means and drives being cooperatively associated so that by moving the end of the rod in one direction the portion of the force absorbing means moves generally in a single plane in the same direction.

5. A power driven hammer as set forth in claim 4, wherein the drives are hydraulic cylinders generally disposed to operate normal to each other and the modulating means are hydraulic control valves generally disposed apart.

6. A power driven hammer as set forth in claim 3, wherein the means for moving the force absorbing means comprise a pair of drives each adapted to move rectilinearly the drives being cooperatively associated with each other and with the force absorbing means so that by simultaneous actuation of the drives the portion of the force absorbing means moves a proportional distance in a single plane, and generally in the same direction as the control means is moved.

7. A power driven hammer as set forth in claim 1, wherein the impacting means is a pneumatic hammer and the force absorbing means comprises seal means disposed on opposite sides of said chamber to minimize leakage of said fluid therefrom, and a split sleeve for fastening said hammer to said inner cylinder.

8. A power driven hammer as set forth in claim 7, wherein the means for moving the force absorbing means comprises a pair of drives each adapted to generally move rectilinearly, the drives being cooperatively associated with each other and the force absorbing means so that by simultaneous actuation of the drives the portion of the force absorbing means may be moved in any direction within only a portion of a single plane.

9. A power driven hammer as set forth in claim 8, wherein the control means comprises a rod and modulating means for operating each drive said rod modulating means and drives being cooperatively associated so 8 and further comprising means for controlling the force of the impact.

12. A power driven hammer as set forth in claim 11, wherein the means for controlling the force of the impact also controls the force applied by the reaction absorbing means.

* t t t 

1. A power driven hammer comprising: means for repeatedly impacting a workpiece, means for absorbing the reaction forces resulting from operating the impacting means, means for holding a portion of said force absorbing means generally within a single plane, means for moving said portion of said force absorbing means in any direction within a portion of said plane, and means for controlling the movement of said portion of said force absorbing means within said portion of said plane, the said force absorbing means comprises a pair of concentric cylinders, one cylinder being slidably disposed within the other and each cylinder having an annular step, said steps registering to form an annular chamber, one of said cylinders being imperforate except for a single port for supplying pressurized fluid to said chamber, the other cylinder being imperforate.
 2. A power driven hammer as set forth in claim 1, wherein said force absorbing means further comprises sealing means disposed on opposite sides of said chamber to minimize leakage therefrom.
 3. A power driven hammer as set forth in claim 1, wherein the means for moving the force absorbing means comprises a pair of drives each adapted to generally move rectilinearly, the drives being cooperatively associated with each other and with the force absorbing means so that the portion of the force absorbing means may be moved in any direction in the portion of a single plane.
 4. A power driven hammer as set forth in claim 3, wherein the control means comprises a rod and a modulating means for operating each drive, said rod, modulating means and drives being cooperatively associated so that by moving the end of the rod in one direction the portion of the force absorbing means moves generally in a single plane in the same direction.
 5. A power driven hammer as set forth in claim 4, wherein the drives are hydraulic cylinders generally disposed to operate normal to each other and the modulating means are hydraulic control valves generally disposed 90* apart.
 6. A power driven hammer as set forth in claim 3, wherein the means for moving the force absorbing means comprise a pair of drives each adapted to move rectilinearly the drives being cooperatively associated with each other and with the force absorbing means so that by simultaneous actuation of the drives the portion of the force absorbing means moves a proportional distance in a single plane, and generally in the same direction as the control means is moved.
 7. A power driven hammer as set forth in claim 1, wherein the impacting means is a pneumatic hammer and the force absorbing means comprises seal means disposed on opposite sides of said chamber to mInimize leakage of said fluid therefrom, and a split sleeve for fastening said hammer to said inner cylinder.
 8. A power driven hammer as set forth in claim 7, wherein the means for moving the force absorbing means comprises a pair of drives each adapted to generally move rectilinearly, the drives being cooperatively associated with each other and the force absorbing means so that by simultaneous actuation of the drives the portion of the force absorbing means may be moved in any direction within only a portion of a single plane.
 9. A power driven hammer as set forth in claim 8, wherein the control means comprises a rod and modulating means for operating each drive said rod modulating means and drives being cooperatively associated so that by moving one end of the rod in one direction, the portion of the force absorbing means moves generally within one plane and generally in the same direction as the rod is moved.
 10. A power driven hammer as set forth in claim 9, and further comprising means for adjusting the force of the impact.
 11. A power driven hammer as set forth in claim 1, and further comprising means for controlling the force of the impact.
 12. A power driven hammer as set forth in claim 11, wherein the means for controlling the force of the impact also controls the force applied by the reaction absorbing means. 